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DNS/DHCP: Add DHCP option 119 parsing
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Also fix some minor bugs in dhcp6 and hncp handling
of domain names

Closes the-tcpdump-group#400
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@fenner
fenner committed Oct 2, 2020
1 parent 5ba8290 commit 27632e1
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Showing 12 changed files with 165 additions and 32 deletions.
1 change: 1 addition & 0 deletions netdissect.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -637,6 +637,7 @@ extern void nfsreply_print(netdissect_options *, const u_char *, u_int, const u_
extern void nfsreply_noaddr_print(netdissect_options *, const u_char *, u_int, const u_char *);
extern void nfsreq_noaddr_print(netdissect_options *, const u_char *, u_int, const u_char *);
extern const u_char *fqdn_print(netdissect_options *, const u_char *, const u_char *);
extern const u_char *fqdn_print2(netdissect_options *, const u_char *, const u_char *, const u_char *);
extern void domain_print(netdissect_options *, const u_char *, u_int, int, int);
extern void nsh_print(netdissect_options *, const u_char *, u_int);
extern void ntp_print(netdissect_options *, const u_char *, u_int);
Expand Down
17 changes: 17 additions & 0 deletions print-bootp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -215,6 +215,8 @@ struct bootp {
#define TAG_NETINFO_PARENT ((uint8_t) 112)
#define TAG_NETINFO_PARENT_TAG ((uint8_t) 113)
#define TAG_URL ((uint8_t) 114)
/* RFC 3397 */
#define TAG_DOMAIN_SEARCH ((uint8_t) 119)
#define TAG_MUDURL ((uint8_t) 161)

/* DHCP Message types (values for TAG_DHCP_MESSAGE option) */
Expand Down Expand Up @@ -514,6 +516,7 @@ static const struct tok tag2str[] = {
{ TAG_NETINFO_PARENT, "iNI" },
{ TAG_NETINFO_PARENT_TAG, "aNITAG" },
{ TAG_URL, "aURL" },
{ TAG_DOMAIN_SEARCH, "$Domain-Search" },
{ TAG_MUDURL, "aMUD-URL" },
{ 0, NULL }
};
Expand Down Expand Up @@ -989,6 +992,20 @@ rfc1048_print(netdissect_options *ndo,
break;
}

case TAG_DOMAIN_SEARCH:
{
const u_char *np = bp;
const u_char *ep = bp + len;
while ( np && np < ep ) {
np = fqdn_print2(ndo, np, bp, ep);
if ( np && np < ep ) {
ND_PRINT( " " );
}
}
bp += len;
len = 0;
break;
}
default:
ND_PRINT("[unknown special tag %u, size %u]",
tag, len);
Expand Down
2 changes: 1 addition & 1 deletion print-dhcp6.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -569,7 +569,7 @@ dhcp6opt_print(netdissect_options *ndo,
tp = (const u_char *)(dh6o + 1);
while (tp < cp + sizeof(*dh6o) + optlen) {
ND_PRINT(" ");
if ((tp = fqdn_print(ndo, tp, cp + sizeof(*dh6o) + optlen)) == NULL)
if ((tp = fqdn_print2(ndo, tp, NULL, cp + sizeof(*dh6o) + optlen)) == NULL)
goto trunc;
}
ND_PRINT(")");
Expand Down
29 changes: 23 additions & 6 deletions print-domain.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -155,10 +155,11 @@ labellen(netdissect_options *ndo,
return(i);
}

/* print a <domain-name> */
/* print a <domain-name> with an explicit end-pointer */
const u_char *
fqdn_print(netdissect_options *ndo,
const u_char *cp, const u_char *bp)
fqdn_print2(netdissect_options *ndo,
const u_char *cp, const u_char *bp,
const u_char *ep)
{
u_int i, l;
const u_char *rp = NULL;
Expand All @@ -170,7 +171,15 @@ fqdn_print(netdissect_options *ndo,
return(NULL);
if (!ND_TTEST_1(cp))
return(NULL);
max_offset = (u_int)(cp - bp);
if (bp) {
max_offset = (u_int)(cp - bp);
} else {
/*
* compression not supported in
* this context (e.g., DHCP6)
*/
max_offset = 0;
}
i = GET_U_1(cp);
cp++;
if ((i & INDIR_MASK) != INDIR_MASK) {
Expand All @@ -179,7 +188,7 @@ fqdn_print(netdissect_options *ndo,
}

if (i != 0)
while (i && cp < ndo->ndo_snapend) {
while (i && cp < ep) {
if ((i & INDIR_MASK) == INDIR_MASK) {
if (!compress) {
rp = cp + 1;
Expand Down Expand Up @@ -225,7 +234,7 @@ fqdn_print(netdissect_options *ndo,
return(NULL);
}
} else {
if (nd_printn(ndo, cp, l, ndo->ndo_snapend))
if (nd_printn(ndo, cp, l, ep))
return(NULL);
}

Expand All @@ -245,6 +254,14 @@ fqdn_print(netdissect_options *ndo,
return (rp);
}

/* print a <domain-name> */
const u_char *
fqdn_print(netdissect_options *ndo,
const u_char *cp, const u_char *bp)
{
return fqdn_print2(ndo, cp, bp, ndo->ndo_snapend);
}

/* print a <character-string> */
static const u_char *
ns_cprint(netdissect_options *ndo,
Expand Down
2 changes: 1 addition & 1 deletion print-hncp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -305,7 +305,7 @@ dhcpv4_print(netdissect_options *ndo,
const u_char *tp = value;
while (tp < value + optlen) {
ND_PRINT(" ");
if ((tp = fqdn_print(ndo, tp, value + optlen)) == NULL)
if ((tp = fqdn_print2(ndo, tp, value, value + optlen)) == NULL)
return -1;
}
}
Expand Down
1 change: 1 addition & 0 deletions tests/TESTLIST
View file
Original file line number Diff line number Diff line change
Expand Up @@ -203,6 +203,7 @@ dhcpv6-ntp-server dhcpv6-ntp-server.pcap dhcpv6-ntp-server.out -v
dhcpv6-sip-server-d dhcpv6-sip-server-d.pcap dhcpv6-sip-server-d.out -v
dhcpv6-domain-list dhcpv6-domain-list.pcap dhcpv6-domain-list.out -v
dhcpv6-mud dhcpv6-mud.pcap dhcpv6-mud.out -vv
dhcp-option119 dhcp-option119.pcap dhcp-option119.out -vv

# ZeroMQ/PGM tests
# ZMTP/1.0 over TCP
Expand Down
32 changes: 16 additions & 16 deletions tests/dcb_ets.out
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
3 04:02:58.010903 LLDP, length 135
Expand Down Expand Up @@ -75,7 +75,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
5 04:03:14.455118 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
Expand All @@ -87,7 +87,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
6 04:03:25.996519 IP6 (hlim 1, next-header Options (0) payload length: 76) :: > ff02::16: HBH (rtalert: 0x0000) (padn) [icmp6 sum ok] ICMP6, multicast listener report v2, 3 group record(s) [gaddr ff02::1:ff46:e884 to_ex { }] [gaddr ff02::2 to_ex { }] [gaddr ff02::202 to_ex { }]
Expand All @@ -100,7 +100,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
8 04:03:26.350998 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) :: > ff02::1:ff46:e884: [icmp6 sum ok] ICMP6, neighbor solicitation, length 24, who has fe80::a00:27ff:fe46:e884
Expand Down Expand Up @@ -176,7 +176,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
17 04:03:35.582218 IP6 (hlim 1, next-header Options (0) payload length: 36) fe80::a00:27ff:fe42:ba59 > ff02::16: HBH (rtalert: 0x0000) (padn) [icmp6 sum ok] ICMP6, multicast listener report v2, 1 group record(s) [gaddr ff02::1:ff00:0 to_ex { }]
Expand All @@ -189,7 +189,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
19 04:03:58.207517 LLDP, length 135
Expand Down Expand Up @@ -256,7 +256,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
21 04:04:15.044685 IP6 (hlim 1, next-header Options (0) payload length: 76) :: > ff02::16: HBH (rtalert: 0x0000) (padn) [icmp6 sum ok] ICMP6, multicast listener report v2, 3 group record(s) [gaddr ff02::1:ff46:e884 to_ex { }] [gaddr ff02::2 to_ex { }] [gaddr ff02::202 to_ex { }]
Expand All @@ -269,7 +269,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
23 04:04:15.831624 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) :: > ff02::1:ff46:e884: [icmp6 sum ok] ICMP6, neighbor solicitation, length 24, who has fe80::a00:27ff:fe46:e884
Expand All @@ -286,7 +286,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
27 04:04:18.745823 IP6 (hlim 1, next-header Options (0) payload length: 36) fe80::a00:27ff:fe46:e884 > ff02::16: HBH (rtalert: 0x0000) (padn) [icmp6 sum ok] ICMP6, multicast listener report v2, 1 group record(s) [gaddr ff02::1:ff00:0 to_ex { }]
Expand Down Expand Up @@ -409,7 +409,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
31 04:04:28.323921 LLDP, length 135
Expand Down Expand Up @@ -531,7 +531,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
34 04:04:51.930199 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
Expand All @@ -543,7 +543,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
35 04:04:53.780244 LLDP, length 135
Expand Down Expand Up @@ -777,7 +777,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
42 04:05:04.283851 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 16) fe80::a00:27ff:fe46:e884 > ff02::2: [icmp6 sum ok] ICMP6, router solicitation, length 16
Expand All @@ -794,7 +794,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
46 04:05:20.296407 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
Expand All @@ -806,7 +806,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
47 04:05:23.875146 LLDP, length 135
Expand Down Expand Up @@ -1038,7 +1038,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
52 04:05:54.004592 LLDP, length 135
Expand Down
2 changes: 1 addition & 1 deletion tests/dcb_pfc.out
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
2 05:02:46.292912 LLDP, length 87
Expand Down
12 changes: 6 additions & 6 deletions tests/dcb_qcn.out
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
2 06:05:25.354704 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
Expand All @@ -19,7 +19,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
3 06:05:30.544746 LLDP, length 86
Expand Down Expand Up @@ -93,7 +93,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
6 06:05:37.009281 LLDP, length 94
Expand Down Expand Up @@ -185,7 +185,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
9 06:05:56.022134 IP6 (hlim 1, next-header Options (0) payload length: 76) :: > ff02::16: HBH (rtalert: 0x0000) (padn) [icmp6 sum ok] ICMP6, multicast listener report v2, 3 group record(s) [gaddr ff02::1:ff46:e884 to_ex { }] [gaddr ff02::2 to_ex { }] [gaddr ff02::202 to_ex { }]
Expand All @@ -198,7 +198,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
11 06:05:56.498519 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) :: > ff02::1:ff46:e884: [icmp6 sum ok] ICMP6, neighbor solicitation, length 24, who has fe80::a00:27ff:fe46:e884
Expand Down Expand Up @@ -277,7 +277,7 @@
Parameter-Request (55), length 17:
Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
Domain-Name (15), Domain-Name-Server (6), Hostname (12), YD (40)
YS (41), NTP (42), MTU (26), Unknown (119)
YS (41), NTP (42), MTU (26), Domain-Search (119)
Default-Gateway (3), Classless-Static-Route (121), Classless-Static-Route-Microsoft (249), Unknown (252)
NTP (42)
17 06:06:04.106458 IP6 (hlim 1, next-header Options (0) payload length: 36) fe80::a00:27ff:fe46:e884 > ff02::16: HBH (rtalert: 0x0000) (padn) [icmp6 sum ok] ICMP6, multicast listener report v2, 1 group record(s) [gaddr ff02::1:ff00:0 to_ex { }]
Expand Down
2 changes: 1 addition & 1 deletion tests/dhcp-mud.out
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@
Subnet-Mask (1), Classless-Static-Route (121), Static-Route (33), Default-Gateway (3)
Domain-Name-Server (6), Hostname (12), Domain-Name (15), BR (28)
NTP (42), Lease-Time (51), Server-ID (54), RN (58)
RB (59), POSIX-TZ (100), TZ-Name (101), Unknown (119)
RB (59), POSIX-TZ (100), TZ-Name (101), Domain-Search (119)
2 12:28:41.318491 IP (tos 0x0, ttl 64, id 10305, offset 0, flags [DF], proto UDP (17), length 338)
62.12.173.114.67 > 62.12.173.121.67: [udp sum ok] BOOTP/DHCP, Reply, length 310, hops 1, xid 0x68c4847, Flags [none] (0x0000)
Client-IP 62.12.173.123
Expand Down
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